The invention is generally concerned with parking barriers, and is specifically concerned with a battery operated, remote controlled parking barrier apparatus having a simple and reliable drive assembly for lifting and lowering a barrier arm.
Remote controlled parking barrier devices are known in the prior art. Such devices generally comprise a support base which is mountable in front of a parking space, and a barrier pivotally connected to the base that is movable into and out of a vehicle obstructing position. The mounting base contains an electric motor, a linkage for converting the rotational movement of the motor shaft into a pivoting movement of the barrier, and a radio-operated battery power supply for remotely actuating the electric motor to lift or lower the barrier connected to the mounting base.
Such parking barrier devices advantageously allow a parking lot or parking garage to reserve individual spaces for VIP's or other individuals. In operation, the mounting base of the device is bolted or otherwise secured on the floor or ceiling of the garage in front of the space to be reserved. The barrier (whether an arm or other structure) is then positioned so as to effectively block an intruding vehicle from entering the reserved space. The person for whom the space is reserved for is given a radio-operated controller not unlike a garage door opener. When a button on the controller is manually depressed, a coded radio signal is transmitted which causes battery power to be supplied to the electric motor within the mounting base of the unit. The motor, through the linkage, proceeds to pivot the barrier out of the vehicle obstructing position (i.e., usually toward the floor of the parking garage). Such parking barrier devices are becoming increasingly popular as they are easily installed, and are effective in reserving parking spaces without the need for a human attendant or an external supply of electrical power. Examples of such devices are disclosed in U.S. Pat. Nos. 5,438,799, 4,934,097, and 4,713,910.
Even though such parking barrier devices are capable of achieving their intended function, the applicant has noted a number of areas in which they might be improved.
For example, many prior art barrier devices utilize a fairly complex linkage between their respective electric motors and barrier arms to lift and lower the arms into and out of a traffic obstructing position. U.S. Pat. Nos. 5,438,799 and 4,713,910 disclose linkages formed from telescopically inter fitting, slotted rails in combination with a cam arrangement, and a rack and pinion, and, pulley and cable arrangement, respectively. Each of these linkages includes a counterweight to minimize the amount of electrical energy needed to lift and lower their respective barrier arms. The mechanical complexity of such linkages not only increases the effort and expense associated with the manufacture of these devices, but also reduces their reliability by providing multiple points where the linkage can jam or otherwise malfunction over time as a result of wear or corrosion.
While U.S. Pat. No. 4,934,097 discloses a somewhat simpler linkage that advantageously uses a motion screw assembly, a plurality of precision made cams is necessary to effect the pivoting motion of the barrier arm. Additionally, the motion screw assembly is located in the barrier arm itself, thereby greatly increasing the weight and hence the power requirement to lift and lower the barrier arm.
In all three of the aforementioned prior art examples, a substantial amount of time and effort is needed to properly adjust the linkage during the assembly of the device so that the barrier arm of the respective device moves within its intended angular limits. Unfortunately, this substantial adjustment effort must be repeated when the arm is accidentally pushed out of alignment. Finally, many prior art devices of this type have no satisfactory provision for preventing damage to the linkage and power supply when the barrier is accidentally blocked during movement. Such a situation might occur if the barrier was actuated while a vehicle was standing in the path of movement of the arm.
Clearly, what is needed is a remote controlled parking barrier device that utilizes a simpler and more reliable linkage between its barrier arm and the electric motor which drives it. Preferably, none of the linkage components would be installed within or attached to the barrier arm itself so as to minimize the weight of the arm and hence the amount of electric power necessary to lift it to a traffic obstructing position. It would be desirable if the linkage of such a device were simple and inexpensive to manufacture and easily adjusted during assembly so that the barrier arm in the final product moved exactly between its intended angular limits. Finally, such a device should have a mechanism for preventing damage to the linkage or circuitry in the event the arm is accidentally obstructed during its movement.